The crew of the Titan submarine knew they were going to die before the explosion, according to a lawsuit worth more than $50 million

The family of a French explorer killed in a submarine explosion has filed a lawsuit for more than $50 million, saying the crew experienced “fear and mental anguish” before the accident and accusing the submarine’s operator of gross negligence.

Paul-Henri Nargeollet was among five people who died when the Titan submarine exploded during a trip to the famous Titanic wreck site in the North Atlantic in June 2023. No one survived aboard the experimental submarine, owned by OceanGate, a Washington state company that has since suspended operations.

According to the lawsuit, Nargeollet, known as “Mr. Titanic,” made 37 dives to the Titanic site, the most by any diver in the world. He was considered one of the world’s most knowledgeable people about the famous shipwreck. Lawyers for his estate said in an emailed statement that the “doomed submarine” has had a “turbulent history,” and that OceanGate did not disclose key facts about the ship and its durability.

According to the lawsuit, the Titan “dropped weight” about 90 minutes after the dive, indicating the team had either attempted or abandoned the dive.

“Although the exact cause of the failure may never be determined, experts agree that the Titan’s crew knew exactly what was happening,” the lawsuit states. “Common sense dictates that the crew knew well before they died that they were going to die.”

The lawsuit further states: “The crew would have heard the sound of carbon fiber cracking, which would have been made even more intense by the pressure of water on Titan’s hull. The crew also lost communications and perhaps power. According to experts, they would have continued descending with full knowledge of the ship’s irreversible failures, experiencing terror and mental anguish before Titan ultimately exploded.”

An OceanGate spokesman declined to comment on the lawsuit filed Tuesday in King County, Washington. Court papers say the defendants are expected to respond to the complaint in the coming weeks. The lawsuit describes Nargeolette as an employee of OceanGate and a crew member on the Titan.

The lawsuit also criticizes Titan’s “modern, contemporary, wireless electronics system,” and states that none of the controllers, controls or gauges will operate without a constant power source and wireless signal.

Although OceanGate named Nargeollet as a crew member, “numerous details about the vessel’s defects and deficiencies were not disclosed and were intentionally concealed,” attorneys from the Buzby Law Firm of Houston, Texas, said in a statement.

Tony Buzbee, one of the attorneys on the case, said one of the goals of the lawsuit is to “get the family answers about how this happened, who was involved, and how the people involved allowed this to happen.”

Following the disaster, concerns were raised about whether Titan was doomed due to its unconventional design and its manufacturer’s refusal to submit to independent scrutiny, which is standard in the industry. Its explosion also raised questions about the viability and future of private deep-sea exploration.

The US Coast Guard immediately launched a high-level investigation, which is still ongoing. A major public hearing, a key part of the investigation, is scheduled to take place in September.

The Titan made its last dive on Sunday morning, June 18, 2023, and lost contact with its sister ship about two hours later. After a search and rescue operation that captured worldwide attention, the Titan’s wreck was found on the sea floor about 984 feet (300 meters) from the Titanic’s bow, about 435 miles (700 kilometers) south of St. John’s, Newfoundland.

OceanGate CEO and co-founder Stockton Rush was piloting the Titan when the vessel crashed. The lawsuit describes Rush as “an eccentric and self-proclaimed ‘innovator’ in the deep-sea diving industry” and names his estate as one of the defendants.

In addition to Rush and Nargeollet, the blast also killed British adventurer Hamish Harding and two members of a prominent Pakistani family, Shahzada Dawood and his son Suleman Dawood.

The company that holds the Titanic’s salvage rights is on its first trip to the wreck site in several years. Last month, Georgia-based firm RMS Titanic Inc. began its first expedition to the site since 2010 from Providence, Rhode Island.

Nargeollet was the director of underwater research for the RMS Titanic. The lawsuit says he was part of an expedition to visit the Titanic site in 1987, shortly after its location was discovered, and that he oversaw the salvage of myriad Titanic artifacts. Lawyers for his estate described him as a seasoned veteran of underwater exploration who would not have participated in the Titan expedition if the company had been more transparent.

The lawsuit blames the explosion on the “continuous negligence, recklessness and carelessness” of OceanGate, Rush and others.

“The deceased Nargeolette may have died doing work he loved to do, but his death — and the deaths of the other Titan crew members — were wrong,” the lawsuit states.